MXPA01004791A - Mould plate of a continuous casting plant - Google Patents

Abstract

The invention relates to a mould plate of a continuous casting plant. Said mould plate consists of copper and comprises a working surface (2) which faces a metal melt (3) or a (partially) solidified metal strand when the continuous casting plant is in operation and at least one cooling surface (5, 5') which is in contact with a cooling medium when the continuous casting plant is in operation. The mould plate has a heat conductivity (W) and extends over a mould length (L) in the direction of casting (x). According to the invention, a layer (7) with a heat conductivity (S) which is less than the plate heat conductivity (W) of the mould plate is applied to the cooling surface (5, 5') in at least one partial area.

Description

PLATE OF MOLDING OR COQUILLA OF A PLANT OF COLADA IN ROPE FIELD OF THE INVENTION [0001] The present invention relates to a mold or mold plate made of copper from a mold for a rope or continuous casting plant, with a work surface in front during the operation of the continuous casting plant to a melt metallic or a partially solidified metallic rope, and at least one cooling surface which, during the operation of the rope-casting plant, makes contact with a cooling medium where the mold plate has a heat conducting capacity and extends in a direction of pouring through a certain length of the shell. BACKGROUND OF THE INVENTION Such a mold plate is known, for example, from EP 0 149 734 Bl. The mold plates have a lower heat conduction capacity and a stronger heat resistance in the upper region than in the lower region. In continuous casting of the metal, especially steel, there is a high wear on the plates of the shell. Therefore, the working surface of the mold plate must be reworked from period to period, after a number of emptying depending on the application conditions of the mold plate. With this, the thickness of the shell plate decreases constantly. For casting or pouring steel strips of high qualitative value, the working temperature must be maintained within a predetermined range. The thickness of the shell plate must also be kept within a permissible thickness margin, which is greater than the minimum thickness required for mechanical reasons. The application of layers, in particular, of nickel layers on the shell plate, as such, is precisely already known. For example, in WO 97/12 708 and Hermann: "Handbook on Continuous Casting", Aluminum-Verlag, Dusseldorf, reference is made to the above. In the state of the art, however, a layer of nickel is applied to the working surface of the shell plate. If essential serves to reduce the wear of the shell in the casting of the rope. SUMMARY OF THE INVENTION The task of the present invention, therefore, consists in continuing the improvement of a mold plate of the aforementioned type that being workable as far as possible more frequently than it is until now, a copper wall thickness is achieved that satisfies in the minimum.

The task is solved because on the cooling surface, at least in a partial zone, a layer with a heat conducting capacity is applied and the heat conducting capacity of the layer is less than the heat conducting capacity of the plate of the Coquilla, the layer in general consists of nickel and the layer is a layer applied without current in a nickel bath on the cooling surface. It is especially advantageous that the layer essentially consists of nickel since the coefficient of expansion to heat of the nickel is less than the coefficient of expansion to heat of a conventional shell plate made of copper. The nickel layer is preferably separated in a nickel bath with additives without current from the cooling surface of the shell plate. For in this case, coatings of the cooling surface are made possible with sharp or sharp contours. Furthermore, with this the thickness of the layer is very uniform and the heat conducting capacity of the layer is markedly less than that of galvanically applied nickel. Regardless of the coating procedure, the heat conducting capacity of the layer must be a maximum of 10% of the heat conducting capacity of the copper in the shell plate.

The insulation properties of the layer are even better, if the layer consists of 5 to 20% phosphorus and in general, without considering the impurities, consists of nickel because in this case the capacity Conductor of the layer is less than 3% of the heat conducting capacity of the shell plate made of copper. The cooling surface may be constructed as a cooling groove disposed on the rear side of the work surface or as a closed cooling bore in reference to a rear side opposite to the work surface. The cooling groove or groove has a floor surface and a side wall selectively the layer can only be applied on the floor surface and / or also on the side walls. If the layer distances from the upper edge in the pouring direction it extends over a layer length and the layer length is less than the length of the shell, the distribution of the temperature can be influenced by the length of the shell. The length of the layer is at least 100 mm, preferably between 300 mm and 500 mm. But alternatively the layer can extend over the entire length of the shell.

DESCRIPTION OF THE DRAWINGS Other advantages and particularities are produced from the following description of an embodiment in relation to the drawings. They show in a principle representation: Figure 1 a running casting chill mold. 2 shows a section of a mold plate with cooling elements. Figure 3, a coating process and Figure 4 another section of shell plate with cooling plate perforations. DESCRIPTION OF THE INVENTION According to FIG. 1, there is a mold casting plant, shell plates 1 made of copper. Each mold plate 1 has a work surface 2 which extends gn in a pour direction x at a certain length L of the mold. Between work surfaces 2, a metal melt 3 is found during operation of the rope casting plant, as a rule a steel melt. The metal melt 3 slowly solidifies a metal cord 4 which is withdrawn in the pouring direction x from the shell plates 1. For the controlled solidification of the metal melt 3 to the casting rope 4, a significant amount of heat must be removed. , the so-called heat of casting, by means of the plates of shell 1. For the removal and conduction of ca} Thus, the chill plates 1 according to FIG. 2 have cooling surfaces 5 which, during the operation of the chill mold, come into contact with a cooling means (not shown). The cooling surfaces 5 are arranged on a rear side 6 on which the work surface 2 rests, they are open towards the rear side 6. They are constructed as cooling grooves 5. The plate of the shell 1 consists as already described. He has mentioned copper. It therefore has a high heat conducting capacity W of, for example, approximately 377 W / mK. In order to provide the chill plate 1 with a higher heat resistance or with a lower joint heat transfer capacity, a layer 7 is therefore applied to the cooling surface 5. The layer 7 has an urging heat conducting capacity S which it is notably less than the heat conducting capacity W of the copper plate. According to the exemplary embodiment, layer 7 consists essentially of nickel to which a phosphorus fraction of 5% to 20% is added. Preferably, the phosphorus fraction is between 9% and 14%, for example 10 to 12%. The heat conducting capacity of the layer can be further reduced when, in addition, up to 30% of silicon carbide is added to the nickel bath in addition to the phosphorus. Besides, only layer 7 contains small impurities. Preferably, it is applied to the layer 7 as shown schematically in Figure 3, so that the shell plate 1 is applied in a nickel bath 8. The layer 7 is then applied without current to the cooling surface 5. Such a nickel layer 7 has a S layer heat conducting capacity which, for example, is only about 5 W / mK. The layer 7 has a layer thickness d, which is understood to depend on the residence time of the shell plate 1 in the nickel bath 8. By means of conventional nickel 8 baths, coarse layers of coats are applicable. between 40 μm and 80 μm, for example 60 μm on the cooling surfaces 5. But in a special nickel bath 8, it is also possible to apply a layer 7 with a thickness of layer d of up to 200 μm. In principle it is possible to completely cover the back side 6, this is technically the easiest to do. But it is also possible to provide the back side 6 before the coating with the layer 7, with a protective layer and only in the places not covered to put the nickel layer 7. For example, have the grooves or cooling slots 5 surfaces of 9th floor and side walls 10, while between the cooling grooves 5 are provided rods 11. It is for example possible to put the layer 7 only on the floor surface 9, but it is also possible to put the layer 7 on the floor surfaces 9 and the side walls 10. Finally it is also possible to place the layer 7 on the entire surface both on the floor surface 9 and on the side walls 10 of the cooling grooves 5, as well as on the rods 11 which remain intermediate. According to Figure 2, there are the two left cooling furrows 5 covered over their entire surface, while the two right cooling furrows 5 have only the floor surfaces 9 covered. It is also possible that the layer 7 extends in the entire length of shell L, this is the case in the outer cooling channels in Figure 2. Alternatively layer 7 may also extend over a length of layer 1 seen from the upper edge 12 in the direction of offset x, which is less than the length of shell L. The length of layer 1 preferably measures between 300 and 500 mm but at least 100 mm, this is the case in the internal cooling channels of figure 2. The shell plate 1 according to the figure 4, differs from the shell plate 1 according to figure 2, because instead of cooling grooves 5, which are open to the rear side 6, it presents cooling perforations 5 '. But here are also the cooling holes 5! provided with the layer 7, where again alternatively, a total or only partial coating on the length of the cooling perforations 5 'is possible. REFERENCE LIST. 1. COCHILLA PLATE 2. WORK SURFACE 3. METAL FUSED 4. METALLIC STRIP 5. COOLING SURFACE / SURFACES 0 COOLING SLOTS. 5*. COOLING SURFACE / COOLING PERFORATIONS. 6. REAR SIDE. 7. LAYER 8. NICKEL BATH 9. FLOOR SURFACE 10. SIDE WALLS 11. VASTAGOS 12. UPPER EDGE. d THICKNESS OF LAYER 1, L LENGTHS. N, S, W CONDUCTIVE CAPACITIES x COLADA ADDRESS.

Claims (10)

1. NOVELTY OF THE INVENTION Having described the invention as above, the content of the following is claimed as property: CLAIMS 1. Coating plate made of copper from a shell for a rope or continuous casting plant with a work surface during operation of the rope casting plant in front or opposite a metal melt or a partially or fully solidified metal rope, and at least one cooling surface which makes contact with a cooling means during the operation of the rope casting plant, where the mold plate has a determined heat conducting capacity and extends in a pouring direction through a length of the mold, characterized in that a layer with a conductive capacity is applied on the cooling surface at least in a partial area. of layer heat and the heat conducting capacity of the layer is less than the heat conducting capacity of the plate of shell and the plate in the essential consists of nickel and the layer is a layer that is applied in a nickel bath without current in a nickel bath on the cooling surface.
2. 2. Mold plate according to claim 1, characterized in that the layer consists of 5 to 20% phosphorus and in the remainder to insignificant nickel impurities.
3. A mold plate according to claim 1 or 2, characterized in that the layer has between 5 to 20% phosphorus, up to 30% volume of silicon carbide and in the remainder to insignificant nickel impurities.
4. The mold plate according to one of the preceding claims 1 to 3, characterized in that the layer has a layer thickness of below 200 μm, in particular between 40 μm and 80 μm.
5. Sheathing plate according to one of the preceding claims 1 to 3, characterized in that the cooling surface is constructed as a cooling groove arranged on the rear side opposite the working surface and that groove is completely laterally coated .
6. Casting plate according to one of the preceding claims 1 to 4, characterized in that the cooling groove has a floor surface and side walls and the layer is only applied to the floor surface.
7. 7. Sheath plate according to one of the preceding claims 1 to 4, characterized in that the cooling surface is constructed as a closed cooling bore on the rear side opposite the working surface. Shearing plate according to one of the preceding claims 1 to 7, characterized in that the layer extends over a determined layer length as seen from the upper edge in the direction of the cast and that layer length is less than the length of the layer. the chilli Casting plate according to claim 8, characterized in that the layer length is preferably 100 mm between 300 mm and 500 mm. Casting plate according to one of the preceding claims 1 to 9, characterized in that the layer extends over the entire length of the shell.